Furnace-door construction.



C. W. WATKINS.

FURNACE DOOR CONSTRUCTION.

APPLICATION FILED JAN.28,1916.

Patented May 16, 1916.

2 SHEETSSHEET l.

dharZeEWdtMns c. w'. WATKINS. FURNACE DOOR CONSTRUCTION.

APPLICATION. FILED JAN.28, 1916.

1 ,1 83,702. Patented May 16, 1916.

2 S'HEETS-SHEET 2- avumutoz a r a mor.

CHARLES WALTER WATKINS, F DORRANCETON, PENNSYLVANIA.

FURNACE-DOOR CONSTRUCTION.

To all whom it mag concern:

Be it known that I, CHARLES W; WAT- KINS, a citizen of the United States, residing at Dorranceton, in the county of Luzerne and State of Pennsylvania, have invented new and useful Improvements in Furnace-Door Constructions, of which the following is a specification.

This invention relates to improvements in furnace doors and has particular application to safety door construction especially adapted for use in connection with the fur naces of steam boilers.

In carrying out the present invention, it ismy purpose to provide a safety door for steam boiler furnaces which will be constructed in such manner that the door, in the event of the same being opened, will be automatically closed in the event of one of the tubes of the boiler bursting, by the action of the steam in the furnace, thereby preventing the escape of steam and hot gases throughthe fire door and causing such gases to pass to the outer air through the smokelstack or flue of the furnace.

It is also my purpose to providea safet door for steam boiler furnaces which may be swung to open and closed positions easily and with a minimum effort on the part of the attendant and which will be automatically held in either of its positions and which will be constructed in such manner that steam escaping from a broken tubeor the like'into the combustion chamber will act upon'the inner surface of the door to hold the latter tightly closed so as to prevent the steam from passing -throughthe door opening and intol'the fire roonit Another object of my invention 1s to provide a doorof theclassdescri-bed which will" embrace'the desired features of simplicity,-

efficiency and durability, which will embody comparatively few parts-and these-so arranged and correlatedas to reduce the possibility of derangement to aminimum, and

which may be manufactured and. installed at small cost.

With the above and other objects in view, the invention consists in the construction, combination and arrangement of parts hereinafter set forth in and falling within the scope of the claim. Y Y

In the accompanying drawings, Figure 1 is a fragmentary front elevation of a steam boiler furnace equipped with a fire doorconstructed in accordance with the present in- Specification of Letters Patent.

-tary-sectional view through the door.

devices.

vention. Fig. 2 is a vertical sectional view the furnace and through which the coal or other fuel may be delivered to the fire chamber. Secured t0 the front wall of the furnace in alinement with the door opening 2 is a frame 3 of a shape corresponding to the shape of the door opening. Inthe present Patented May 16, 1916.

Application filed January 28, 1816. Serial No. 74,800.

re j

instance, the inner end .of the frame 3 is formed with an outwardly projecting flange 4 lying in face to face contact with the wall fof the furnace around the door opening and passed through the flanges and thefurnace wall 1 are securing bolts 5 or other fastening from the wall of the furnace a short distance and secured to the respective vertical side portions of the flange 4: and projecting outwardly from such portions, are bearing "brackets 6 havingthe outer end portions thereof formed with horizontally alining bearing openings 7 disposed slightly above the horizontal center line of the frame 3. In the present instance, each bearing bracket 6 comprises lower and uppensections 8 and 9. respectively placed edge to edge and formed on the confronting edges of the re- The frame? projects oircwardly spective sections are a tongue and groove 10 and 11 designed] to interfit so'as to hold the sections against relative movement. 12

designates a horizontal pivot rod arranged across the outer edge of the frameB and having the ends thereof turned downas at 13 and journaled in the bearing openings 7 in the brackets 6.. In this form of my invention'the turned down ends of the pivot rod are surrounded by bushings .14 constructed of suitable material and is designed to take the Wear.

Fastened upon the horizontal pivot rod 12 in some suitable manner and adapted to close the outer end of the frame 3 is a door 15 capable of swingingmovement into the frame to open the door opening so that the fuel may be delivered to the fi're chamber of the furnace. The connection between the pivot rod and the door is arranged at apoint above the horizontal center line of the door, as clearly illustrated in Figs. 1 and 2 of the drawings, while formed on the upper edge of the door above the pivot rod is a flange 16adapted to abut the upper edge of the frame 1 and the portions of the side edges of the frame above the pivot rod when the door is in closed position, while formed on the lower edge of the frame and the side edges thereof below the pivot rod is an inwardly extending flange 17 adapted to engage the corresponding edge portions of the door when the door is closed. These flanges cooperate with each other to form a fluid tight connection between the door and the frame so as to prevent the ingress of air to the fire chamber and the discharge of any gas from the fire chamber to the fire room.

The outer ends of the pivot rod 12 project beyond the respective bearing brackets and fastened to these ends are arms 18 arranged at right angles to the rod and ad justably mounted upon the arms 18 are counterweights 19 adapted to counterbalanee the door when in open position so as to hold the door in such position against the action of gravity. The outer ends of the arms 18 are connected with the handle bar 20 spanning the space between the arms whereby the door may be swung to open and closed positions.

Normally, the door is held in closed position under the action of gravity and when it is desired to open the door, the arms 18 are swung by means of the handle bar 20, thereby rotating the pivot rod and swinging the lower portion of the door into the frame 3. The counterweights on the arms assist in opening the door and act to hold the door in open position. To close the door the handle bar 20 is operated in the reverse direction and as the arms pass the center of the pivot rod the door drops to closed position under the action of gravity and remains in such position.

Should a boiler tube burst or any other abnormal condition arise in the boiler, or the fire chamber, the gases entering the fire chamber will act upon the door to hold the latter tightly against the flange 17 and hold the flange 16 on the upper portion of the door tightly against'the top portion of the frame, thereby preventing the escape of the gas into the fire room and compelling such gas to pass through the smoke stack or flue to the outer atmosphere. In the present instance, the door 15 comprises an outer or front plate 21 and an inner liner The liner 22 is spaced apart from the front plate 21 and the confronting faces of the plate and liner are formed with inter-fitting lugs 23 and are connected to each other by means formed in the front plate 21 are air-openings 26 and pivoted upon the front plate is a.

wicket 27 movable to cover and uncover the air openings 26.

Formed on the rear sideof the liner 22 adjacent to the lower edge thereof is a lug 28 adapted to abut the top wall of the frame in the movement of the door to open position and this lug 28 acts to prevent the door from assuming a horizontal position when swun inwardly. Thus, the door presents a surface to the interior of the fire chamber, when such door is open, upon which steam or other gases may act to automatically swing the door to closed position so as to prevent the escape of gas to the fire room in the event of abnormal conditions arising in the fire chamber.

It will be seen that I have provided a safety door for steam boiler furnaces which may be manufactured and. installed at practically the same cost as the ordinary furnace door, while the door may bereadily opened and closed and will be automatically closed in the event of an abnormal condition arising in the furnace. This door will be found especially useful on the steam boiler furnaces of seagoing vessels, locomotives, buildings and, in fact, may be used upon any steam boiler furnace. I

When my improved safety door is used upona locomotive boiler furnace, I employ means for holding the door in closed position. In the present instance, I have shown this holding'means in the form of a chain 29 having one end fastened to anieye bolt 30 carried by the upper portion of the frame 3 and the other end equipped with a. hook 31 adapted to engage thehpper portion of the door to hold the door closed.

While I have herein shown and described one preferred form of my invention by way of illustration, I wish it to be understood that I do not limit or confine myself to the precise details of construction herein described and delineated, as modification and variation may be made within the scope of the claim and without departing from the spirit of the invention.

I claim:

In a safety door for steam boiler furnaces, the combination with the front wall of the furnace having a door opening therein, of a frame secured to the front wall of the furnace in alinement with the door opening therein and corresponding in shape to the shape of the door opening and projecting beyond the front wall of the furnace, bearing The liner is brackets disposeu at opposite sides of said frame and projecting outwardly beyond the outer edges of the side pieces of the frame,- a horizontal pivot rod carried by said brackets and arranged across said frame and disposed at a point above the horizontal center line of the frame, a door secured to said pivot rod, a flange on the upper portion of said door adapted to abut the corresponding edges of said frame, a flange on the outer portion of said frame adapted to be engaged by the corresponding portions of said door and cooperating with the first-named flange to form a fluid-tight connection between the door and the frame, means carried by the inner side of said door and adapted to engage the top Wall of said frame in the movement of the door to open position to prevent the door from assuming a horizontal position whereby the door willpresent a surface to the interior of the furnace against Which the gases may act to close the door, and counterbalancing means for said'door to hold the latter in open position against the action of gravity.

In testimony whereof I affix my signature in presence of two Witnesses.

CHARLES WALTER WATKINS.

Witnesses:

FRANK GLA'rz, JOHN HARNED.

copies of this patent may be obtained for five cents each, by addressing the Washington, D. 0."

Commissioner of Patents, 

